KR20120134420A

KR20120134420A - Apparatus and methods for producing hydrocarbons from carbon dioxide

Info

Publication number: KR20120134420A
Application number: KR1020110053308A
Authority: KR
Inventors: 목영선; 좌은진
Original assignee: 제주대학교 산학협력단
Priority date: 2011-06-02
Filing date: 2011-06-02
Publication date: 2012-12-12
Also published as: KR101292932B1

Abstract

PURPOSE: A hydrocarbon production apparatus and method using carbon dioxide is provided to use a dielectric barrier discharge activation catalyst to obtain hydrocarbon from the carbon dioxide. CONSTITUTION: A hydrocarbon production apparatus comprises the following: a pipe(5) forming a body of a reactor; an internal electrode(3) and an external electrode(4) installed inside the reactor; an inlet pipe(1) inserting reaction objects into the reactor; a catalyst layer(7) filled with a dielectric barrier discharge activation catalyst; a power source(6) supplying the current to the electrodes for producing plasma; a heater(8) heating the reactor; and a grounding unit(9) connected to the external electrode.

Description

Apparatus and methods for producing hydrocarbons from carbon dioxide

The present invention relates to an apparatus and method for producing hydrocarbon energy by reacting carbon dioxide with hydrogen or water vapor. More specifically, the present invention relates to an apparatus and a method for activating a catalyst through discharge in a state in which a catalyst is charged in a dielectric barrier discharge device, so that a hydrocarbon generation reaction can effectively occur even at low temperature and atmospheric pressure.

As the Kyoto Protocol on Carbon Dioxide Emissions came into effect in 2005 as a countermeasure against the ongoing global warming, Korea is expected to become a member of the CO2 reduction obligation since 2013, so it is urgent to prepare efficient measures to use domestic carbon dioxide. In addition, the successful development of technology for efficient use of carbon dioxide has led to the development of the Clean Development Mechanism (CDM) project, especially in developed countries. The ripple effect is expected to be large.

As one method for the treatment of carbon dioxide, a method of producing a synthetic gas from a mixed reforming reaction of natural gas, carbon dioxide, and steam, and using the same, to produce useful chemical raw materials and transport fuels, in particular, Synthesis of methanol, which is an important chemical raw material using synthetic gas, or a method of manufacturing synthetic oil by the Fischer-Tropsch reaction has been increasingly used as an alternative for efficient utilization of carbon dioxide.

Conventional carbon dioxide treatment techniques include dry ice production through absorption, concentration and pressurized cooling and methane gas production using a catalyst. Dry ice manufacturing technology through absorption, concentration, and pressurized cooling requires enormous energy in each step and carbon dioxide is not converted into a new material, but only the state of the material is converted into a solid phase, which is not a fundamental treatment method.

In addition, the production of methane gas using a conventional catalyst is a method that consumes a lot of energy because it is operated at a high temperature and pressure, and a lot of investment costs are required because the characteristics of the reactor material should be excellent by operating at high temperature and high pressure. In addition, catalyst deactivation due to caulking is also pointed out as a big problem.

In order to solve the above problems, the present inventors have invented a method of activating the catalyst by discharging the catalyst in the dielectric barrier discharge device in a state in which the hydrocarbon generation reaction can occur effectively even at low temperature and atmospheric pressure. .

The present invention seeks to provide an apparatus and method for producing hydrocarbons from carbon dioxide using a dielectric barrier discharge activation catalyst.

The present invention is a device for producing a hydrocarbon from carbon dioxide by using a dielectric barrier discharge, the tube (5) forming the body of the reactor, the internal electrode (3) and the external electrode (4) provided in the reactor, the reactant into the reactor Plasma is generated by supplying a current to the inlet pipe (1) for introduction, the catalyst layer (7) in which the dielectric barrier discharge activation catalyst is filled in the pipe (5), the inner electrode (3) and the outer electrode (4). It relates to a device for producing hydrocarbons from carbon dioxide using a dielectric barrier discharge, characterized in that it comprises a power supply (6) and a ground portion (9) of the current connected to the external electrode.

In addition, the first step of filling the catalyst in the reactor consisting of a tube (5), the reactant is introduced into the reactor through the inlet pipe (1); A second step of heating the introduced reactant with a heating device (8); And a third step of applying a high voltage power source 6 to the internal electrode 3 and the external electrode 4 provided in the reactor to produce a hydrocarbon. It relates to a method for producing a hydrocarbon from carbon dioxide using a dielectric barrier discharge comprising a.

The present invention uses a catalytic reactor activated by a dielectric barrier discharge, thereby greatly increasing the conversion reaction rate of carbon dioxide, and the reaction can be effectively performed even at a relatively low temperature compared to a general catalytic process. In addition, it can be applied to industrial combustion facilities such as thermal power plants and boilers, which are the main sources of carbon dioxide, and can be utilized as a greenhouse gas reduction device and a high purity energy production device.

1 is a schematic diagram of a dielectric barrier discharge activated catalytic reactor.
2 is a schematic diagram of an experimental apparatus for an embodiment of the present invention.
3 is a graph comparing the carbon dioxide conversion of the dielectric barrier discharge activation catalyst and the simple catalyst process on an alumina supported nickel catalyst.
4 is a graph showing the carbon dioxide conversion rate according to the nickel content supported on alumina.
FIG. 5 is a graph comparing the carbon dioxide conversion of the dielectric barrier discharge activation catalyst and the simple catalyst process by nickel content on the zeolite-supported nickel catalyst. FIG.

The conversion of carbon dioxide and hydrogen mixtures (or carbon dioxide and water vapor mixtures) to hydrocarbons on the catalyst shows very high activation energies, requiring high reaction temperatures and pressures to achieve sufficient rates of reaction. However, in the present invention, the catalyst is activated in the dielectric barrier discharge device in the state in which the catalyst is activated through the discharge, that is to lower the reaction activation energy, so that the hydrocarbon generation reaction can occur effectively even at low temperature and atmospheric pressure and It is about a method.

The present invention relates to an apparatus for producing a hydrocarbon from carbon dioxide using a dielectric barrier discharge, more specifically,

The dielectric barrier discharge causes the gas phase to be in a plasma state, where the reactant molecules are excited, dissociated or ionized to exhibit high reactivity. The catalyst adsorption behavior of excited molecules is different from the adsorption behavior of the ground state molecules. Also, when carbon dioxide, a reactant, is adsorbed on the catalyst, the carbon-oxygen bond energy decreases and can be easily dissociated by dielectric barrier discharge. React to produce hydrocarbons. The present invention allows the catalyst to be activated through excitation, dissociation and ionization by dielectric barrier discharge, so that carbon dioxide can be rapidly converted into hydrocarbon energy even under low temperature and atmospheric pressure.

The generated hydrocarbon can be discharged to the outside through the outlet (2) of the reactor, the discharged hydrocarbon can be analyzed by gas chromatography.

The reactant may be a carbon dioxide and hydrogen mixture or a mixture of carbon dioxide and water vapor, and may further include nitrogen in the carbon dioxide and water vapor mixture. This is to prevent the condensation of water vapor, and the proportion of nitrogen in the total gas may be 90 to 95%.

The ratio of carbon dioxide and hydrogen in the carbon dioxide and hydrogen mixture may be 1.25 to 1: 5, and the ratio of carbon dioxide and steam in the carbon dioxide and steam mixture may be 1:10 to 1: 100.

As the electrode, all conductive metals may be used, and the internal electrode 3 may be used in various forms, and may be selected from the group consisting of a general metal wire, a thin metal tube, a metal rod, or a spring. In one embodiment of the present invention, a stainless rod was used as the internal electrode 3.

The external electrode 4 may be a metal thin film as described above, may be used by coating a metal on the outside of the tube (5), it may be covered with a thin metal plate or a coating using a metal paste. One embodiment of the present invention used a copper foil (foil) as the external electrode (4).

The tube 5 is a tube that forms the body of the reactor and serves as a dielectric, and any material having dielectric properties may be used. In one embodiment of the present invention, a quartz tube is used.

The power supply 6 may use an alternating current or pulsed power, and may use an alternating current power of high voltage or high frequency.

The catalyst of the catalyst layer 7 may be alumina-supported nickel or zeolite-supported nickel, the content of nickel supported on the alumina may be 1-7%, and the content of nickel supported on the zeolite may be 2.5-10%, in this case There is an advantage to increase the conversion rate of carbon dioxide even at low temperatures.

The tube 5 may be mounted by filling non-reactive quartz wool.

The heating device 8 may be further installed so that the reactor is heated, an electric furnace or the like may be used. Operating the heating device may include maintaining a temperature of 180 ~ 260 ℃. The present invention is based on the dielectric barrier discharge using the activation catalyst, it is possible to increase the conversion rate of carbon dioxide even at such a relatively low temperature.

In addition, the present invention is the first step of filling the catalyst in the reactor consisting of a tube (5), the reactant is introduced into the reactor through the inlet pipe (1); A second step of heating the introduced reactant with a heating device (8); And a third step of applying a high voltage power source 6 to the internal electrode 3 and the external electrode 4 provided in the reactor to produce a hydrocarbon. It relates to a method for producing a hydrocarbon from carbon dioxide using a dielectric barrier discharge comprising a.

The ratio of carbon dioxide and hydrogen in the carbon dioxide and hydrogen mixture may be 1: 2.5 to 1: 5, and the ratio of carbon dioxide and steam in the carbon dioxide and steam mixture may be 1:10 to 1: 100.

The catalyst may include alumina-supported nickel or zeolite-supported nickel, the content of nickel supported on alumina may be 1-7%, and the content of nickel supported on zeolite may be 2.5-10%, in which case even at low temperatures It can increase the conversion rate of carbon dioxide.

In addition, the temperature can be maintained at 180 ~ 260 ℃ by the heating device 8 in the second step, the present invention is due to the dielectric barrier discharge using the activation catalyst, carbon dioxide even at a relatively low temperature as described above To increase the conversion rate.

In the third step, the high voltage may include 6 to 11 kV.

The generated hydrocarbon can be discharged to the outside through the outlet (2), the hydrocarbon can be analyzed by gas chromatography.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are intended to illustrate the contents of the present invention, but the scope of the present invention is not limited to the following examples. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

< Example >

1.Dielectric Barrier Discharge activated catalytic reactor

The dielectric barrier discharge activated catalytic reactor used in the present invention was fabricated from a quartz tube (18 mm outer diameter; 15 mm inner diameter) and 6.4 mm thick stainless rod, as shown in FIG. The outer wall of the quartz tube is wrapped with copper foil, and the length of the quartz tube wrapped with copper foil is 120 mm. A catalyst of 1-2 mm diameter is filled between the inner wall of the quartz tube and the stainless rod. The volume of packed catalyst is 17 cm ³ .

An alternating high voltage (6-11 kV) of frequency 1 kHz was supplied to the stainless rods and the copper foil was grounded. Silicon plugs are installed on both sides of the quartz tube, through which high voltage is supplied and gas is leaked. A dielectric barrier discharge activated catalytic reactor was installed in the electric furnace to control the reaction temperature. Catalysts were prepared by impregnation, and two types of catalysts were used. One is nickel (Ni / alumina) supported on alumina, and the other is nickel (Ni / zeolite) supported on zeolite.

In addition, the specific surface area of alpha alumina used in the present invention was 195.7 m ² / g, and the specific surface area of zeolite beta was 550-600 m ² / g. The molar ratio of Si and Al in zeolite beta was 130.

The reactants supplied to the dielectric barrier discharge activated catalyst reactor of FIG. 1 were a carbon dioxide + hydrogen two-component mixture or a carbon dioxide + nitrogen + steam three-component mixture. The CO ₂ / H ₂ ratio was 1/4 and the CO ₂ / H ₂ O ratio was 1/10. Water vapor was supplied saturated with nitrogen in water vapor. When steam was used, the reason why nitrogen was used together was to prevent condensation of water vapor, and the proportion of nitrogen in the total gas was 95%. The total flow rate was 250 cm ³ / min based on room temperature and atmospheric pressure. As shown in FIG. 2, the reactants were introduced into the quartz tube, preheated, and then introduced into the catalyst. After the reaction was made the product was analyzed by gas chromatography. The voltage for causing the dielectric barrier discharge was measured with a high voltage probe and a digital oscilloscope.

2. Conversion of Carbon Dioxide to Methane

3 is a graph showing the rate at which carbon dioxide is reduced by hydrogen and converted to methane (CH ₄ ), which is a hydrocarbon, at a reaction temperature in the range of 200-300 ^° C. The conversion rate at the time of use and the conversion rate when the dielectric barrier discharge was caused by applying an alternating current high voltage of 10.3 kV were compared. The reaction in which methane is produced from CO ₂ can be expressed as follows.

CO ₂ + 4H ₂ = CH ₄ + 2H ₂ O, ΔH _300K = -165.10 kJmol ^-1 (1)

As the reaction temperature increases, as shown in FIG. 3, the conversion rate of carbon dioxide increases, and when a high voltage of 10.3 kV is applied, the conversion rate of carbon dioxide increases more rapidly. As an example, the difference in conversion with or without dielectric barrier discharge at 260 ^° C. is as much as 40% because the dielectric barrier discharge activates a catalytic reaction to convert CO ₂ to CH ₄ .

3. Alumina Supported Conversion rate of carbon dioxide under nickel catalyst

(1) Figure 4 is a graph showing the conversion rate of carbon dioxide according to the nickel content supported on alumina. In this experiment, the nickel content was in the range of 0-12.5% and the alternating high voltage was fixed at 10.3 kV. In general, the reaction temperature is a key parameter in the catalysis. As shown in FIG. 4, when the nickel content is 5% or less, the conversion rate of carbon dioxide gradually increases with the reaction temperature. However, when the nickel content was higher than 7.5% and 12.5%, the maximum conversion was shown in the range of about 200-200 ^o C, and the carbon dioxide conversion tended to decrease as the temperature was further increased. According to the embodiment of FIG. 4, carbon dioxide can be methanated at all nickel contents, but the preferred titer nickel content is determined to be about 5%.

(2) On the other hand, on an alumina-supported nickel catalyst having a nickel content of 5%, when the AC high voltage was 10.3 kV and the reaction temperature was 240 ^° C., the conversion rate of carbon dioxide to methanol by water vapor was about 20%. However, when AC high voltage was not supplied, the conversion rate of carbon dioxide by water vapor was negligibly small. The reaction of converting carbon dioxide to methanol by steam is expressed as follows.

2CO ₂ + 4H ₂ O = 2CH ₃ OH + 3O ₂ (2)

Carbon dioxide can be converted to methanol as shown in this scheme, but the reaction does not occur at all since the high energy barrier cannot be overcome without the dielectric barrier discharge. However, the reaction occurs when the catalyst is activated through the dielectric barrier discharge to overcome the reaction energy barrier. Although the carbon dioxide conversion reaction by steam is slower than the carbon dioxide conversion reaction by hydrogen, the conversion rate can be further improved by installing the reactor in multiple stages or by increasing the reactor size. Since a conversion rate of about 20% appears in one reactor, the volume of the reactor may be increased five times or more, or the number of reactors may be five or more.

4. on zeolite Supported Conversion rate of carbon dioxide under nickel catalyst

FIG. 5 is a graph comparing the carbon dioxide conversion of the dielectric barrier discharge activation catalyst and the simple catalyst process by nickel content on the zeolite-supported nickel catalyst. FIG. In this experiment, the nickel content was changed to 2.5% -10%, and the AC high voltage was fixed at 9.3 kV. The reaction temperature was experimented in the range of 180-260 ^o C. In Fig. 5, the black symbols (circles, triangles, squares, rhombus) are the result when there is no dielectric barrier discharge, and the white symbols (circles, triangles, squares, rhombus) are catalyst activated by the dielectric barrier discharge. This is the result when it is done.

As shown in Fig. 5, the zeolite-supported nickel catalyst exhibits very little carbon dioxide conversion at a temperature in the range of 180-260 ^° C. without the dielectric barrier discharge. However, when an AC high voltage of 9.3 kV was supplied to cause the dielectric barrier discharge, the carbon dioxide conversion was greatly increased at all nickel contents. When the nickel content was 7.5 and 10%, the conversion at the reaction temperature of 260 ^° C. was found to be 90% or more. In order to achieve such a high conversion, the nickel content should be 7.5% or more.

1: inlet tube, 2: outlet, 3: internal electrode, 4: external electrode, 5: tube, 6: power source, 7: catalyst bed, 8: heating device, 9: ground of current

Claims

A device for producing hydrocarbons from carbon dioxide using dielectric barrier discharges, the tube (5) forming the body of the reactor, the internal electrode (3) and the external electrode (4) provided in the reactor for introducing the reactants into the reactor A power source for generating a plasma by supplying a current to the inlet pipe 1, the catalyst layer 7 filled with a dielectric barrier discharge activation catalyst inside the pipe 5, the internal electrode 3 and the external electrode 4 ( 6) and a ground portion (9) of a current connected to the external electrode.

The apparatus of claim 1, wherein the reactant is a carbon dioxide and hydrogen mixture or a carbon dioxide and water vapor mixture.

3. The apparatus of claim 2, further comprising nitrogen in the carbon dioxide and water vapor mixture.

2. The apparatus of claim 1, wherein the catalyst is alumina supported nickel or zeolite supported nickel.

The apparatus of claim 4, wherein the nickel content of the alumina is 1-7%, and the nickel content of the zeolite is 2.5-10%. 6.

The apparatus of claim 1, further comprising a heating device (8) for heating the reactor, wherein the temperature of the heating device is maintained at 180 to 260 ° C. .

Filling the catalyst into a reactor consisting of tubes (5) and introducing a reactant into the reactor through an inlet tube (1); A second step of heating the introduced reactant with a heating device (8); And a third step of applying a high voltage power source 6 to the internal electrode 3 and the external electrode 4 provided in the reactor to produce a hydrocarbon. Method of producing a hydrocarbon from carbon dioxide using a dielectric barrier discharge comprising a.

8. The method of claim 7, wherein the reactant is a carbon dioxide and hydrogen mixture or a carbon dioxide and water vapor mixture.

10. The method of claim 8, further comprising nitrogen in the carbon dioxide and water vapor mixture.

8. The method of claim 7, wherein the catalyst is alumina-supported nickel or zeolite-supported nickel.

The method of claim 10, wherein the content of nickel supported on the alumina is 1-7%.

The method of claim 10, wherein the content of nickel supported in the zeolite is 2.5 to 10%.

8. Method according to claim 7, characterized in that the temperature is maintained at 180 to 260 DEG C by the heating device (8) in the second step.

8. The method of claim 7 wherein the high voltage in the third step is 6-11 kV.